Android devices come in a wonderful variety of shapes, sizes, colors, and capabilities. They can differ from one to another in terms of operating system-level features, pre-installed apps, and innovative interface experiments. Why is there such a difference?

The Android Open Source Project gives device manufacturers a lot of leeway in creating unique features that will draw customers. Compare this to iOS, where Apple controls the hardware and platform (although this has its own advantages).

In this guide we’ll take a look at how new versions of Android are released, how manufacturers use them in their devices, and some of the most intriguing changes they’ve baked into their products.

Instead, it uses the Linux kernel as its base and adds a runtime to execute apps along with other libraries to it. Apps and system services use these resources, and the result is the Android we all know. This hierarchy is shown in the below image from the Android Developers portal.

Image Credit: Google

Android is similar to Windows in that, once a particular version has been through development and testing, it’s “released.” Its source code is pushed to the repositories of Android’s developer portal, where manufacturers can freely download and use it. Let’s take a closer look at how Android receives its ongoing enhancements.

Google Releases AOSP

“Stock” Android is the Android that results from its development in the open, collaborative environment Google has established. As Google coordinates the development of Android, it will make regular releases to the Android Open Sourse Project (AOSP). The output of this project is the source code for the complete mobile operating system we know as Android.

It’s important to know what “operating system” means in this context. It refers to a combination of underlying platforms (the kernel, basic software libraries, etc.) as well as some applications. Together these are what the industry refers to “stock Android,” and it has become very much in vogue for devices to ship with something close to it. Manufacturers, including Google, need to create images for their own devices.

At the other end of the spectrum, because Android’s source code is available for anyone, third parties can compile itHow to Compile Your Own Linux KernelHow to Compile Your Own Linux KernelCompiling your own Linux kernel is one of those geeky, technical things, right? We've already covered a few reasons why you might want to do this -- now is the time to try it yourself!Read More for devices of their choosing without Google’s blessing. There are two examples of this you might already be familiar with.

The first is devices made by Amazon, which we’ll get to in a later section. These use Android as their underlying operating system, while at the same time using their own app store and main launcher interface.

For a free and cross-platform option, you can download and install Android Studio and run the included SDK Manager. It allows you to download the programming resources for each release of Android (as shown in the below image), including a “system image” for each.

Once complete, one of Android Studio’s tools is the “Android Virtual Device” manager. Look for the toolbar button labeled (“AVD Manager”) as shown below:

Once it appears, you can click “Create Virtual Device…” to quickly create a virtual device in two steps. First, select a device profile. Don’t spend too much time thinking about it, as it only provides parameters such as screen size and resolution:

Then choose which version of Android it should run:

Click Finish, when the virtual device is created, launch it with the play button in the AVD Manager:

Once the virtual device is running, you can see the standard layout and collection of apps each version of Android provides. Comparing two versions, 5.1 (Lollipop, shown below at left) and 7.1 (NougatHow to View the Default Apps on Android NougatHow to View the Default Apps on Android NougatAndroid's default app management has been lacking in the past, but Nougat includes a handy new default app manager.Read More, at right) side-by-side, you can see they provide many of the same apps. (Aside from Google’s apps, which, as discussed, require an additional review and agreement.)

These include Contacts, Phone (which includes the dialer), Camera, Browser (on older versions), Chrome (on newer versions), and some accessories like Clock and Gallery. This set of applications enables you to enjoy the basic benefits of your smartphone.

But it represents a pretty barebones experience. This is why most manufacturers will do some measure of customization work. As mentioned, AOSP includes the work of Google as well as other contributors. Once released, manufacturers can download the source code and make their adjustments to it, as described in the following sections.

Manufacturers Adjust AOSP for Hardware

When manufacturers are ready to begin work on a new device, they’ll begin with a copy of the source code from the AOSP project. Among the first things they’re likely to add are any drivers required to operate special hardware on their device.

You can see an example of this in the Note 5’s S-Pen. This is a device that talks to the phone, even when there is no physical contact. So Samsung created a driver that accepts input from this accessory.

The hardware may require some additional software as well. The S-Pen, for instance, accepts multiple configuration options. Manufacturers will create these components (like Settings screens, as shown in the above image) and add them to the Android codebase from AOSP.

However, once all the hardware is accounted for, their work isn’t necessarily done.

Manufacturers Customize AOSP’s Features

Lastly, a manufacturer will also make additions to create a unique experience for their customers. This can include installing default themes and pre-loading particular applications right out of the box. Like the items mentioned in the last section (drivers, config screens, etc.), they can’t be uninstalled.

You may notice these hiding among your Library in the Google Play app. They may have a note saying they can’t be uninstalled. Otherwise they may have a button like “Deactivate” (as shown in the below image) or “Uninstall Updates” in place of the usual “Uninstall.”

It is this category where manufacturers will really differentiate themselves. In the following sections, we’ll take a look at some of the leading manufacturers and the customizations they’ve made to their recent flagship devices.

Common Customizations Made by Android Manufacturers

In the sections below, we’ll be looking at two to six of the most useful and unique features of each phone. These are all pre-installed on the device, and many are exclusive.

Samsung

As a leading manufacturer of electronics and other goods, Samsung has the scale to really invest in developing features to set their devices apart.

First of these is Bixby, a voice-enabled assistant that competes with Amazon’s Alexa and Google’s Assistant. Once you configure what types of information you want to see (as shown in the below image), Bixby’s artificial intelligence is supposed to learn the more you use it. It will make recommendations and present them to you in the form of cards shown on the home screen.

Bixby has four main additional functions, as follows:

Voice, which enables voice control. Samsung notes that you’re able to zero in your commands more closely with Bixby, for example, requesting to open the camera app in a specific mode.

Vision, which allows you to point the camera at something (shown in the image below) and get relevant info about it, such as translations for foreign words or shopping links for products.

Home, the aforementioned collection of cards with contextual info such as your schedule or prompts to launch apps based on past habits or other triggers. One example of this is ordering an Uber straight from a calendar entry.

Reminder, which prompts you based on conditions such as a time or location (shown in the image below).

Samsung has also created the DeX environment, an attempt to make your Samsung phone your only computer. DeX is another alternate skin to Android (in addition to the company’s “TouchWiz” interface) that contains many of the trappings of a desktop: Start-style launcher button, movable desktop icons, a taskbar, and multiple application windows.

The newest addition to Samsung’s line-up, the Note 8, includes a feature called Live Message. It allows you to use the Note’s included stylus to draw animated messages or spruce up pictures. These are converted to GIF images, so you won’t need to worry about the recipient also having a Note 8 or using a special app, which is often the case with features like this.

While it no longer offers any phones, Amazon is nonetheless a big player in the market for Android tablets. The company’s Fire OS is technically Android under the hood, as it uses the same base layer as other manufacturers. But the user interface is heavily customized and accents the device’s target as a content consumer rather than a creator.

In the past this was even more accentuated, as the home screen was basically a “coverflow”-style carousel of the content in your library. In recent releases however Amazon has taken a step back from that approach and made the launcher look a little more traditional.

However, Alexa integration is also bound to a long-press on the app drawer (shown in the below image), indicating it’s importance.

One of the most fundamental differences in Amazon’s devices however is how you obtain apps for them. A Fire tablet doesn’t have access to the Google Play Store out of the box. It has access to the Amazon AppstoreGoogle Play vs. Amazon Appstore: Which Is Better?Google Play vs. Amazon Appstore: Which Is Better?The Google Play Store isn't your only option when it comes to downloading apps -- should you give the Amazon Appstore a try?Read More — a wholly different marketplace with a different selection of apps. Major apps are likely to be available in both places; a quick look at the “Best Sellers” from Amazon includes standards like Minecraft, Netflix, Facebook, and Angry Birds.

Getting the Amazon Appstore on a non-Amazon device requires sideloading as well, though Amazon makes it really easy. The APK file is available for download, and they actually provide instructions for sideloading the app.

The fact that you have to turn off the “Unknown Sources” security restriction prevents some nervous users from installing it, but it’s an otherwise painless process. Simply open the APK file from a file manager (above left) and accept the installation (above right).

Users can select from among a number of supported apps to include news, app reminders, and social media updates. Recommendations from HTC’s Sense Companion (discussed in the next section) are also an option, as shown in the below image:

The Sense Companion adds assistant-style learning to the feed concept, offering users suggestions for things like restaurants, system tuning, or helpful reminders. The example HTC often references, shown in the image below, is a reminder to charge your phone when it notices upcoming meetings on your calendar.

The company’s Sense interface is overall very close to a stock Android launcher. Most changes are focused on simplification of both function and look-and-feel. But the theming engine allows for a good amount of aesthetic customization, yet their overall layout and control of the user interface doesn’t stray far from stock.

The image below, accessible from the home screen configuration for the U11, demonstrates some of the themes available to change the look of your device to suit your taste.

HTC has also made an effort recently to use the applications of other companies where it makes sense. For example, in recent devices (such as the HTC 10HTC 10 ReviewHTC 10 ReviewThere's little to complain about with the HTC 10, aside from the mediocre battery life and quiet speakers. But there's nothing about it to get excited about, either.Read More) the company replaced home-grown apps such as HTC Gallery and Music with their Google counterparts.

In this spirit, HTC also offers Amazon’s Alexa as a choice for the virtual assistant on their devices.

LG

LG has produced good flagship phones that have largely flown under the radar to date. While it doesn’t have a “trademark” feature per say, the company does implement some clever additions to the overall experience while also providing some enhanced applications.

First, there’s the Floating Bar on the LG V30. This is an always-on-top, slide-out toolbar containing your selection of items:

You can also customize what shortcuts or apps are accessible on the Floating Bar. They could be: Settings screens, favorite contacts, controls for music players, or the ability to take a quick screenshot.

LG phones also have Always-On Displays. When configured, the phone will reduce its brightness (to prolong battery) and display the lockscreen when the phone would normally go to sleep. Users can set the display from among a variety of layouts, which can include the time, date, and other bits of information.

In many ways the V30 targets the mediaphile. Its high-quality audio set-up is evidence of this, as is its photography features.

The first of these is Graphy, which allows you to select from among a number of pre-configured photo settings. Graphy presents famous pictures to users, who can then apply the settings such as light sensitivity, aperture, and shutter speed from those images all at once.

It allows you to match the conditions you’re in with the look you want based on photos that have already done just that. It’s a unique, intuitive way to prevent users from struggling with settings to get just the right combination for given shot.

LG also provides a standalone app that allows you to browse and add additional samples to your library:

Similarly, Cineffect is a collection of video filters with the names of various types of movies. For example, “Romantic Comedy” is bright with soft lighting, while “Noir” is dark and brooding. The camera app allows you to apply these filters directly (shown below), with the added bonus that they will not degrade video quality.

The latest MIUI version 8 has an interesting feature called Dual Apps that allows users to configure apps with multiple profiles, even if those apps don’t expressly support it. For example, using different Skype accounts normally requires you to log out of one account and into another.

But this feature allows you “clone” an app, which sets it up in a sort of sandbox with its own data and settings. MIUI 8 will list the apps it supports in this fashion within a Settings screen. Flipping the switch for the app will create the second profile.

When setting this space up you’ll have the option “import” files and apps from your primary space. You switch using a launcher icon and/or an entry in the notification tray, as shown in the below image.

Mi Mover is an application to assist users in migrating to their new Xiaomi device. Through a device-to-device connection, the app will move data including:

System Data, including Contacts, Messages, and Call History

Apps and App Data

Files, including Photos, Media, and Documents

Once you set up the sender and receiver for the move, you can select which items will transfer. Choose them either as a category (shown below at left) or for each item (shown below for apps at center and SD card files at right).

Some of these imports happen simply by signing into a new phone with your Google account. But the items within System Data are often not among them. This sort of bonus functionality is what users enjoy about the community ROMs, which will attract them to the devices as well.

Xiaomi is looking to expand its ecosystem into a broad range of devices, not unlike Samsung. Mi Home is part of this. It’s an app to connect to all the different Mi home automation devices, including:

Network equipment, including a gateway device that doubles as a network speaker

The app allows users to control and monitor connected devices. The precise capabilities depend on the device on the other end. But examples include reading filter life on air purifiers (shown in the above image) or turning lights on. You can also combine actions into “scenes” that users can activate with a single tap.

When taking a screenshot of a long web page, for example, you can use Scrolling Screenshot to pan down and capture the entire page. In other words, it doesn’t limit screenshots strictly to what’s on the screen at the time. Straightforward, but pretty useful!

Motorola

Before smartphones were a thing, Motorola made two of the must-have phones of their time: the iconic Star-TAC clamshell, and it’s svelte successor the Moto RAZR.

They provide enhanced hardware features (such as a speaker, projector, or camera8 Phones With the Best Cameras Today8 Phones With the Best Cameras TodayWith advancements in hardware and a demand for multi-function devices, smartphone cameras can indeed replace standalone cameras.Read More, as shown in the above image). Some also have companion apps to enhance their functionality. For example, the recently-launched Moto Gamepad links to the Moto Game Explorer app, which contains a list of Gamepad-compatible games.

Lastly, Motorola includes an assistant feature called Moto Voice. It’s not a full-blown assistant in the way that Samsung’s Bixby is. Instead, it’s a different way of activating Google Assistant that can be activated even when the screen is locked.

It does provide some other functionality, though, like reading out your text messages to you when you’re driving.

Google

The Android image Google ships with their own hardware isn’t strictly “stock Android.” But it’s very close from both the visual and usability perspective.

It’s not surprising Google would integrate their own Assistant in a high profile way for their own hardware. And they did, by mapping Assistant to the Active Edge available on both Pixel 2 models. Like Edge Sense on the U11, this feature launches an app in response to a squeeze of the phone’s sides. In this case, the app in question is Google Assistant.

Unfortunately you’re not able to configure the squeeze gesture to do other things (as shown in the below image). This is a clear sign of Google pushing the Assistant app as the user’s path of choice to content. This convenient, one-handed gesture positions Assistant as the best option for quick interactions like checking messages or sending texts.

Google Lens is able to match objects in the phone’s camera viewfinder and begin searching for additional information about them. The phone will combine all Google’s indexed data with its latest investments in artificial intelligence and machine learning.

Another rather unique feature of the new Pixels is Now Playing. It’s a sort of always-on Shazam in that it identifies songs anytime music is playing nearby. The title and artist display on the Pixel’s always-on lock screen or as notifications.

And unlike comparable services, the Pixels have a local database of popular songs. It won’t need to contact a Google server to identify them, saving your mobile data.

Variety is the Spice of Android

Over the course of this guide we’ve examined the wide variety in the Android market. Its the open platform that allows manufacturers to make different form factors, software features, and other little changes.

There are many in the industry who point at these and cry, “Fragmentation!” But that’s what allows innovation as the Samsungs and Googles of the world compete. Add to this the open source AOSP project and a vibrant developer community, and Android gives you a multitude of options.

Do you have a favorite feature from your own Android device? Anything you wish you you had from other Android devices? From iOS even? Share your thoughts on the broad spectrum of Android functionality, along with any tips you have, in the comments below!

Aaron has been elbow-deep in technology as a business analyst and project manager for going on fifteen years, and has been a loyal Ubuntu user for almost as long (since the Breezy Badger). His interests include open source, small business applications, integration of Linux and Android, and computing in plain…